Graphene oxide and chemical crosslinker enhanced water-based polyurethane elastomer nanocomposites

Graphene oxide (GO) and a water-based crosslinker (WCL) are hydrophilic, hence, were systematically employed to reinforce water-based elastomers (WBEs) using water-based polyurethane (WPU). Structural investigations, including Raman spectroscopy, indicated strong interfacial interactions between WPU and GO or GO-WCL, evidencing synergistic bonding. Mechanical characterization by uniaxial tensile testing and dynamic mechanical analysis (DMA) showed substantial property enhancements, with an increase of ∼183 - 308 MPa in tensile modulus (at 3% strain) and a 35 - 39 MPa improvement in tear strength for GO-WBE nanocomposites at 1 wt% loading. The dynamic storage modulus increased to 368.37 ± 19.71 MPa (GO/WPU) and 503.23 ± 15.91 MPa (GO/WPU/WCL) at 1 wt% loading, compared with 117.41 ± 16.42 MPa for neat WPU. Notably, WCL incorporation reduced ultimate tensile strength (UTS), ultimate elongation, and tan δ (damping factor), whereas GO-only nanocomposites exhibited improved performance, including increased UTS across all loadings. Thermal analysis further showed that WCL-based nanocomposites had a higher glass transition temperature than the GO-only systems. Thermal decomposition temperatures also increased with GO loading, with GO-only nanocomposites outperforming WCL-based counterparts in several cases. This work provides insight into the crosslinking effects of GO and the synergistic GO-WCL integration within the WPU matrix. Both GO and WCL increased the crosslink density ( Cd ), which strongly correlated with enhancements in the mechanical and thermal properties of the nanocomposites. Comparatively, GO-only nanocomposites exhibited superior mechanical and thermal performance relative to WCL-infused systems, despite their lower Cd. In general, these GO-WBE nanocomposites demonstrate substantial recycling and sustainability potential for high-performance technical applications. Overall, the robust reinforcement of the WPU matrix through GO and WCL integration positions GO-WBE nanocomposites as strategic materials for sustainable deployment across robotics, coatings, automotive, aerospace, maritime, textiles, sensors, electric vehicles (EVs), and artificial intelligence (AI) manufacturing.